


in a weird voice, sing of love

by minimiwrite



Category: Cardfight!! Vanguard
Genre: Fluff and Humor, M/M, Too much hand holding, lots of hand holding
Language: English
Status: Completed
Published: 2018-11-21
Updated: 2018-11-21
Packaged: 2019-08-27 07:23:55
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,615
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16697983
Author URL: https://archiveofourown.org/users/minimiwrite/pseuds/minimiwrite
Summary: In which Kai loses a fight, Kamui realizes something terrifying, and Aichi spends more time blushing than he really thinks is appropriate. (Kai and Aichi announce their engagement. Things go just about as you’d expect with Kamui around.)





	in a weird voice, sing of love

Kamui prided himself on being someone that his friends could rely on, but today, after he realized that he had snoozed his fifth alarm unconsciously, he thinks that he might have to change that sentiment to being someone that his friends could always rely on after maybe around noon. As a newly minted professional Vanguard player, he was able to set his own schedule, but this lead to some pretty bad sleeping habits, and thus, days like this, where he was flying past red lights and apologizing to cars on the street as he made his mad dash to Card Capital. Usually, he’d stop by if he had the time (after he finally dragged himself out of bed at about two in the afternoon), but Aichi had invited him and everyone else to the shop, saying that he had something important to announce. He skidded in, stumbling into Card Capital completely out of breath.

“You’re late.” Misaki had a stern look on her face. “You’re the last one here, Kamui.”

“I’m sorry, my alarms went off but I slept through them, and, then I ran a few red lights and almost got hit by a,” he blabbered as he walked in further, looking around for Aichi. He noticed him close to Kai, both of them speaking to Naoki. “Ah, Aichi nii-san!”

Aichi turned, smiling. “Kamui-kun! You made it! I thought you might have forgotten.”

“I wouldn’t forget you, Aichi nii-san!” He responding, flashing Aichi a smile of his own, before turning to Kai. “I wouldn’t miss a chance to fight you either, Kai! I’ve been practicing and I’ll completely blow you away today!”

His bold declaration was met with a smirk and a simple ‘aa’ from Kai. There wasn’t much more to say as he reached into his pocket to grab his deck before he was interrupted by Misaki stepping in, a slightly annoyed (but ever fond, though she would never admit that) expression on her face.

“Aichi, Kai, what was it that you wanted to show us so badly?” At Misaki’s words, the rest of their shared friends gathered around the couple, some of them loudly wondering the same thing (Morikawa and Naoki, they were the loud ones, not Kamui).

With a small smile, Aichi lifted up his hand to proudly show a elegant silver band around his ring finger, and Kai silently showed a matching gold ring on his. “Kai and I are engaged.”

There was a pause as everyone registered the information. Misaki gathered herself first, smiling at Kai and Aichi, quietly, before congratulating them. The rest of their friends crowded around them, asking them question after question (it was Aichi who had proposed, it was in private, and no, Morikawa, Aichi did _not_ propose using a Vanguard card box, why would you even ask that, but yes, it was during a cardfight, please stop laughing Miwa).

Staring at the two of them, he couldn’t help but get a little nostalgic. Kamui always thought that Aichi had the patience of several deities, considering just how long he waited for Kai to notice and understand his own feelings. Aichi was a gentle, patient person (and that’s what Kamui loved about him the most, but still, there should be limits and in his honest opinion, that limit should have been Kai Toshiki) and wanted Kai to move at his own pace, never hurrying him or asking more of him that he could handle. They had progressed through their relationship how they wanted to, sometimes stumbling, but always together, and everyone knew it was more a question of ‘when’ than a question of ‘will they’. Most of the Card Capital regulars even had bets for when they would finally become boyfriends (Shin-san had won big, much to Kamui’s annoyance at the time. He thought that they’d get their acts together after Kai had brought Aichi back from the moon, since Kai seemed to finally accept his own feelings, but alas, it took them another few months to come into the store holding hands). But watching them now, standing tall together, accepting congratulations from their friends and rivals, Kamui found himself almost tearing up. They all really came this far, huh?

“Aichi onii-san! Congratulations!” He grabbed Aichi’s hands in his own, and before he knew it, the tears were spilling out (he didn’t want be crying at a happy time like this, but…), at full force. The overflow of happiness for Aichi and Kai, he guessed, was just too much all of a sudden.

“Ahh, Kamui-kun, thank you!” Aichi was beaming, a little teary himself, like the day they had won the Asia Circuit together as Team Q4, and before he knew it, Kamui found himself being hugged. “Thank you...!” The hug was brief but genuine, and Kamui almost didn’t want to let go, but he drew away, drying the leftover tears from his eyes.

“So, you two lovebirds,” Miwa had popped up between Kai and Aichi, ignoring Kai’s pointed look and the surprised noise that Aichi made, slinging his arms around their shoulders with a bit of a sly grin. “Who’s taking who’s last name? Should I start calling Aichi Kai-kun instead?”

Aichi choked on thin air, coughing violently as Miwa immediately hit his upper back. Once the fit subsided, he looked up, his cheeks tinged pink. “Oh, we haven’t really thought about that at all.” Aichi’s cheeks were growing progressively pinker and pinker as he continued. “It’s sort of an outdated practice but… if I had to choose… I guess maybe… I’d take Kai-kun’s last name…?” He paused for another second, getting out a strangled “Kai Aichi doesn’t sound too bad...” before burying his face into his free hand.

At Aichi’s last few words, Kai stiffened, looking away. “I wouldn’t… mind taking Aichi’s last name either.” Neither of two moved after that, although there was a muffled squeak from Aichi that sounded like a suspicious ‘Se-sendou Toshiki?!’.

Miwa laughed, clearly enjoying the newly engaged couple’s flustered reactions, before leaning down and saying with a wiggle of his eyebrows, almost conspiratorially, “Maybe you should decide it the way that we always do. With a cardfight!”

Misaki immediately walked over and peeled her husband off of Kai’s backs with a disapproving frown. “Don’t say something like that, they should talk about it some more. It’s an important decision, and they might not even want to take each other’s last names later.” Miwa laughed as she pulled him to a standing position right behind them, cheerfully catching her hand in his and lacing their fingers together.

“You’re only saying that ‘cause you’re scared they’ll actually do it like that, Misaki!” He chirped out mischievously. “I’m sure they know I’m–”

“I think that it’s a great idea!” Kamui blurted out, trying to avoid Misaki’s heated gaze (he can literally feel the daggers digging into his skin, he’s probably going to die later isn’t he) and Miwa’s disbelieving stare. He put his arms up in a sign of surrender, but continued. “It’s a real test of wills! And plus, I wanna see Aichi nii-san kick Kai’s butt again!”

“Yeah, it sounds like a really cool idea!” Naoki chimed in. He pumped a fist up into the air. “Vanguard is what brought you two together right? It’s only natural that you should decide it like this!”

“Hah… I don’t know.” Aichi finally was able to lift his face up from his hands, face still glowing a soft pink. “It’s a bit much… to consider right now.” From his side, Kai, who was busy looking away from everyone, made a sound of agreement.

“Why not though?” Naoki seemed genuinely confused as to what could be holding the two back. “If both of you are okay with either outcome, then what’s the point of waffling over it? You should just have fun and enjoy yourselves!”

“That was surprisingly wise, coming from you, Naoki.” Miwa dryly cut in, rubbing small circles into his forehead. “But this is a pretty permanent decision, you know? I think they should talk about it, not just cardfight.”

“They can talk and cardfight!” Kamui triumphantly announced. “I mean, Aichi nii-san proposed by cardfighting, didn’t he? This is pretty much the same thing!”

“That’s… true.” Aichi murmured, glancing at Kai, who just gave Aichi a neutral stare back (Kamui always wondered what was going on in their heads when they looked at each other like that). “I guess that we can just change our minds later, too.”

“Yeah! Aichi nii-san! Good luck!” Kamui thumped his back encouragingly, eyes sparkling (how long has it been since he’s last seen Aichi fight? It’s always too long).

Naoki ran up to Aichi as well, beaming. “You’ve got this man!”

Aichi gave Naoki and Kamui a weak smile before turning to his fiance. “Are you okay with this?”

Kai shrugged. “We can always change our minds, like you said.” There was a softness to his voice that Kamui wasn’t used to, a sense of reassurance that he’d never thought he’d hear from Kai, of all people (Kamui couldn’t help but remember their first tournament together for a split second, how immature they all were, how different things are now). The soft look on Kai’s face morphed into something a little more fierce and familiar however, as Kai grabbed his deck from his pocket. “I’m ready to fight you, Aichi.”

“Wait, wait, wait, just a moment, you’re actually doing this?!” Miwa stammered out, butting in between Kai and Aichi, clearly shocked by how his gentle teasing turned into the mess in front of him. “Shouldn’t you two like… actually talk? Like, you know, most people?!”

“I don’t think it’s a bad idea.” Aichi smiled a little bashfully before fishing his own deck out his pocket as well. “A lot of important things came to us during Vanguard fights. And... I want to fight Kai-kun again too!”

Misaki pinched the bridge of her nose as she sighed and pointed farther back in the shop (Kamui saw a hint of a smile underneath her hand). “We have standing tables right there.” She paused for a moment. “You’re lucky that Kourin is filming today.”

Aichi laughs, a little nervously. “Kourin probably wouldn’t approve of using cardfights for this kind of thing, huh?”

“Not at all.” Miwa shook his head. “When we were trying to decide how we were going to do last names and wedding stuff, Suiko and Takuto offered to do some weird card readings for us and she basically chased them out of the room with a spare mic.” Miwa stopped, tilting his head thoughtfully for a moment. “But maybe that’s ‘cause it’s Suiko and Takuto.”

“Well, she’s not here!” Kamui butted back in, bouncing on the heels of his feet. “C’mon, Aichi nii-san! After you’re done with Kai, I want to fight you too!”

With a few laughs, the group moved around a standing table, and for a moment as Aichi’s eyes met Kai’s, Kamui felt a rush of nostalgia; it was like he was back in middle school again, when Team Q4 could all meet up and play the hours away whenever they wanted (he misses it, a lot. Times were simpler back then, but at the same time, he wouldn’t give what was happening in front of him for anything). A familiar call brings him back to the present.

“Stand up!”

“The!”

“Vanguard!”

The fight started. Both Aichi and Kai were incredibly talented players, and everyone found themselves on the edge as they played their cards (when Blaster Blade came out, Kamui couldn’t help but cheer louder; Naoki and Miwa joined in his hollars). Time passed, but it felt like mere seconds from when they had decided to fight. Eventually, both Kai and Aichi were at five damage, smiling just as wide as they had as they announced their engagement. Kamui cheered as Aichi dealt another point of damage, and held his breath as Kai slowly turned over his final damage trigger. And it seems that–

“It’s my win, Kai-kun.” Aichi’s smile had become so wide that it almost looked painful. After quickly gathering up his cards, he reached out his hand towards his fiance, smiling when Kai reciprocated the gesture and took his hand in his.

“Aa.” Kai, though he had lost, seemed not to mind at all. The two almost seemed like they didn’t realize they were at Card Capital, so wrapped up in their own little world (Kamui wishes that he and Emi could have something like that someday, it looks nice to be able to just drift off in someone else’s person).

“Aichi, you do realize he’s Sendou-kun now, right?” Miwa called out teasingly. “You won, so it’s your last name, right?”

“O-oh!” Aichi looked up to his fiance a little bashfully. “Uh, Sendou-kun…?” Aichi let go of Kai’s hand, turning away, ears turning slightly red. “Ah, this is… sort of strange…”

“It’s weirder that you still call him Kai-kun when you’re about to get married, I think.” Naoki chimed in, with a bit of a laugh. “Why don’t you just call him by his given name already? _Sendou_ , ” Naoki drew out the name, clearly teasing his friend, “calls you Aichi.”

“I, uhm, I…” Aichi squeaked out. “I, just, it’s just what I’ve been calling him...”

“That’s enough.” Misaki stepped in, though she also had a bit of a lopsided smile to her face, as though she was trying to keep herself from laughing. “Let them do what they want.”

The rest of their friends agreed, though a few more light teasing remarks were made throughout the rest of the day. Kamui was able to finally get the fight that he wanted from Aichi (he lost, but he couldn’t even be bothered to care when Aichi was having so much fun as well) and another fight against Kai, and more against the others that were there. Before long, he realized that it was getting dark out.

Kamui was about to jump in and ask for another fight from Kai before he left when a sudden cold chill freezes his good mood as he slowly came to realize... if Aichi and Kai Toshiki were getting married, then they would be related to each other as husband and husband. That means that his wonderful Emi, who is the younger sister of one Sendou Aichi, would have a new older brother. And then, when they got married one day (Kamui finds himself growing beet red just at the thought of marrying her, what a magical time that would be), that means… Kamui found himself lacking the usual bravado while staring at Kai– no, Sendou, now, he thinks, screaming internally– with the realization…

_Sendou Toshiki is basically his new older brother._

_Holy shit._

Kamui literally had no idea how to process or use the information that his brain had just recognized. It wasn’t that he hated Kai (not anymore at least) but the fact that Kai Toshiki was going to become a part of his family that truly shocked him.

What was he supposed to do now? He still wanted that fight, but it’s… with… there’s nothing to do but move forward, the way he always did (that thought left him wincing, but he figures it can’t be that bad). He approaches Kai apprehensively but quickly, trying to shake the feeling of unease in his stomach. Aichi and Kai were again holding hands, and taking a quick break from the cardfights that were happening around them, drinking some soda concoction that Shin had brought in. Aichi noticed him first and smiled, waiting patiently for Kamui to speak first. He raised up a shake-y hand to point at Kai, and without realizing it, began yelling loud enough to be heard by the entire store.

“Fight me! Sendou onii-san!”

Many things happen at once. Aichi chokes on his drink. Kai (Sendou, he reminds himself, even while it makes him want to die a little to think about what’s happening even more) drops the cup he’s holding, the juice spilling out onto the carpet of Card Capital. Some of it even gets onto his and Aichi’s shoes, but it doesn’t seem like either of them notice. Misaki stops and turns to Kamui, looking at Kamui as though he’s grown a second head. Miwa, Morikawa, Izaki, and Naoki all pause in their movements for a millisecond, before erupting into laughter. Kamui himself has turned a shade of red that beets would envy, screaming at himself internally.

“K-Kamui-kun…” Aichi finally wheezed out, trying his hardest not to go into another coughing fit. “What… did you just say?”

He kept pointing at Kai. “I-I said that I wanted to fight you, Sendou onii-san!” He tried to tune out the new wave of uncontrollable hysterics that Miwa, Naoki, and the others fell into as he desperately fought down the blush on his face. After Kamui realized that his face may permanently be stained red, he decided to switch tactics and redirect everyone’s attention back the potential cardfight (considering the group he’s around, he really thinks he can’t be blamed for trying). “I’ll definitely win this one! It’s our last fight of the night!”

“Onii-san?” Kai’s face was contorted with confusion; he still hadn’t even noticed that his drink was currently on the floor, staining the carpet.

Kamui couldn’t help but wince at Kai’s words as though they caused him physical pain. “Argh, well, Aichi is my onii-san, and if he’s marrying you, that means–” he hesitated, but only ever slightly, “you’re also my onii-san now!” He stared at Kai, who still seemed confused. Did he have to spell it out for him? Does he really have to say it? “Ugh, once me and my goddess get married, we’ll be related! We’ll be a family!”

“You… just accepted it?” Kai still seemed rather confused. “That I’m… your older brother?”

“Don’t say it like that!” Kamui reared back, as though the words had burned him. “It’s worse when you say it!” Gritting his teeth, he continued. “I trust Aichi onii-san and he chose you! That’s all! So you’re just gonna have to get used to it, Sendou onii-san! Actually, you should be honored to be related to me, the Great Kamui!” He puffed out his chest as he spoke. “A rising star in the professional Vanguard scene and the one that’ll take down your throne!”

To Kamui’s utter surprise, a small smile appeared on Kai’s face in response to his outburst (he can’t tell what Kai’s thinking, did he really not understand anything that Kamui had said before? It was all just the obvious). “Aa.”

“Kamui, that’s so cute, how you just accepted him in as your new older brother!” Miwa interrupted before Kamui could say anything in response. He had a smug grin, almost like a cheshire cat, as he slung an arm over Kai’s shoulder. “Sendou onii-chan, please take good care of me too!”

“Miwa!” Both Kai and Misaki’s voices rang out in the shop as the others started laughing again, some semblance of calm returning to the card shop after Kamui’s initial outburst.

In the end, Kamui got his cardfight (he won this time, though it was a close game with a few miracle triggers involved), the carpet got cleaned, and all their friends starting to get ready to go back home. Kamui was exhausted by the day’s events, slightly swaying on his feet and seriously considering calling a taxi instead of doing the entire trek back home. His laziness won out, but before he could dial a number into his phone, Aichi waved him over to a more secluded area of the shop.

“Kamui, about earlier…” Aichi paused, blinking. “I just wanted to thank you.”

“Ah? What for?” He frowned, confused to what Aichi was talking about. “If you’re talking about putting Sendou onii-san in his place, you beat him today too, Aichi onii-san.”

“Oh, no, that’s not it.” Aichi laughed a little breathlessly. “I meant, for telling Kai– I mean, Sendou-kun– that we’ll be a family together. He was worried that people wouldn’t approve.” There was a sad, tired glint in Aichi’s eyes that seemed to reflect more stress than he let on (Kamui wondered how many times Kai and Aichi must of had the same conversations, considering who to tell, how to tell them, and how much it weighed on the two of them). “It meant… a lot to me too.”

Kamui stared at Aichi. To him, he just said the obvious, what he had understood after thinking about it for a while. It didn’t really seem like something he needed to be thanked for, but at the same time, seeing the genuine appreciation in Aichi’s eyes, he couldn’t bring himself to brush it off (and if he’s being honest, getting praised by Aichi about something other than Vanguard made the corners of his mouth turn up). “It’s no problem, Aichi onii-san!” He grinned. “Tell Sendou onii-san that just because he’s my brother now that I’m not gonna go easy on him!”

Aichi let out another gentle laugh as he pulled back, leading Kamui back into the bigger main group saying their farewells. He watched Aichi go back to Kai’s side, and the two bade their other friends goodbye. Kamui had to admit, they were a good match, always encouraging each other to be the best they could be, pushing, but never forcing each other to grow, and balancing the other’s flaws (though they weren’t nearly as good of a couple as him and Emi, of course). His lips curled up into another smile, unbidden. He didn’t mind being part of a family like this one, if it could stay just like this for now.

**Author's Note:**

> idk what wedding traditions are like anywhere i just really like the idea of matching rings im sorry if its super super wrong sob
> 
> thanks for reading this mess


End file.
